Cover for turbine-buckets.



A. F. MACDONALD. COVER FOR TURBINE BUGKETS. APPLICATION FILED 1m. 2a, 1901.

Patented 0011.20.1908.

4 V 7: 3. {It}:

Witness es.- I In v enl. or;

fl/ xander'F? Ma cdona/d,

, by iv UNITED sTAfrus I ENT OFFICE.

ALEXANDER F. MACDONALD, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

' covnn FOR TuBBnin-nucxn'rs.

To allwhom 'it may concern:

Be itknown that I, ALEXANDER F. MAC- DONALD, a citizen of the United States, residing at Schenectady, county of Schenectady,

State of New York, have invented certaln new and, useful Improvements in Covers or Baffle-Strips for Turbine-Buckets, of which the following is a specification.

The present invention relates tothe cover or bafile-strip for the ends of buckets of elas 'tic fluid turbines, and has for its object to im rove their construction.

11 carrying out my invention, the buckets are mounted upon a suitable support and may be individually secured thereto, formed integrally therewith, cast into the support or secured by any suitable means. The buckets may extend radially with respect to the wheel.

obtained. This ribbon is supported by the ends of the buckets and forms one of the walls of the bucket spaces. By using a long strip and windin it round and round the whee I avoid all oints in the covering and the labor incident thereto. By making it flexible it unnecessary to use bending dies as a part of the manufacture. Thisresults in greatly decreasing the cost of the construction and at the same time, simplifies the wheel. The ribbon is-made thin so as to bevery flexible and readil applied to the bucket ends. Before'the ri bon is applied to the buckets it is suitably perforated by means of a punch, which perforations when the ribbon is mounted on the wheel, are adapted to register and receive the bucket securing means. Ordina rily, the perforations will be equally spaced, and in any event should be' of suflicient size to permit of the ribbon being slipped over thetenons or other securing means, and enable one turn to lie in contact with the other.

The perforations may be made of any suitable shape. For example, they may have straight sides and curved ends, corresponding to the curved surfaces of the buckets, or they may be made round or rectangular, depending upon the character of the means employed to secure the succestlve layers to the Specification of Letters Patent. application filed March 28, 190p sai-m No. scams. 1

ishe Patented Oct. 20, 1908.

bucket wheel or drum. By making the ribbon thin,'these perforations can. easily be made by an ordinary index punch and die, and bein thin, can readily be made without danger o burring the stock when the punch passes through the strip. I may use steel or phosphor-bronze for this urpose, or an other material which is capa ing the centrifugal strains to which it will be su jected in practice. The outer end of the ribbon may be secured in place by one of the same tenons or other securing means employed to hold the cover in place, or a s ecial ineans'for the urpose may be'tprovide When the rec ends of the buckets are parallel with the axis of the wheel, the ribon will be made perfectlyv straight, and of a width suflicient to cover the bucket endsand project slightly be ond the sharpened edges on one or both sides the object of the latter being to protect sai sharpened edges. When the free ends of the buckets are made 1e of withstan r on an incline for the purpose of providing the necessary spaces between the buckets to. accommodate the elastic fluid, the sides of "the ribbon will be made slightly curved tocompensate for the difference in diameterbetween the inlet and the discharge sides of the bucket. This can readily be done by using a ribbon that is a little thicker on one side than on the other and passing the same through rollers or dies, which decreases the thickness of the ribbon on one side and in so doin elongates said side and causes the finproduct to be curved on an arc of large radius, which radius would vary with the amount of inclination of the bucket ends, the diameter of the wheel, etc.

In the accompanying drawing, which illustrates certain of theeinbodiments of the invention, Fi ure 1 is a front elevation of a bucket wheed; Fig. 2 is a section of a wheel showing the covering mounted in place with tenons on the buckets for securing the same in place; Fig. 3 is a partial sectional "view in the plane of. the wheel; Fig. 4 is a detail view showing acovering a plied to wheel buckets having inclined-en s; Fig. 5 is a plan view of a metal ribbon provided with perforations throu h which thecover-securmg means extend; ig. 6 is a bin view of a ribbon before it is perforate and which is adapted to be mounted upon wheel buckets .may provide means such as smal place, as shown in Fi of the construction shown in Fig. 4, and Fig. 7 is adetail view of a slight modification of the cover securing means.

1 is a wheel, keyed or otherwise secured to the shaft 2 and provided with radial buckets 3. Surrounding the buckets ,and wound thereon in layers and forming the outer wall of the bucket spaces, is a metal strip or ribbon 4. This r1 bon is provided with 'erforations 5. 'I e buckets 3 are provided with integral tenons 6 which extend through the perforations in the ribbon and are riveted over at their outer ends to secure said cover in lace. Instead of providing the buckets with tenons, I may employ screws or other means 7 for holding the cover in 7. In this .case,'the cover may be applie while'unperforated, and said perforations made afterwards. Preferably, the outer-end 8 of the ribbon terminates at a point adjacent to one of the tenons or other securing means so 'as to hold the same in lace and prevent it from bending outward? under the efiects of centrifugal force. 'l he inner end 9 may be located at a point between two buckets. When, for any reason, the buckets are widely spaced, I

rivets for holding the ends of the ribbon, which rivets pass through said ends in a radial direction and are riveted over to hold the same in place. 5

When thefturbine is of the radial flow type and the buckets are arranged in concentricf circles, the same form of coverin may be used except that the ribbon woul be wound edgewise in suitable winding mach-ines, and to a diameter corresponding to the diameter of the particular row of buckets to which it is adapted to be attached. As now constructed, these windin machines are capable of winding a small ri bon edgewise and at the same time maintaining the same thicknem of avoiding any tendency of the ribbon to buckle.

The invention is applicable to machines "operating on. the impact or reaction prinof the impact' 'ciple, or upon a 'modlfication or reaction principle.

using a metal ribbon for a cover and 'ng it in the mannerspecified, I avoid lb sses in stock which would result if made in small pieces. The cover can be a plied to the buckets more-rapidly than t e constructions heretofore proposed, and the i in the cost of labor is very consider- In accordance with the provisions of the patent statutes, I have described the princlple of operation of my invention, to therwith theagparatus which I now consi er to re resent ebest embodiment thereof; but I ire to have understood that the appastock at all points and ratus shown is only illustrative, and that the invention can be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, is,-'

1. An elastic fluid turbine comprisin a plurality of buckets and a support there or, in combination with a ribbon that is wound in layers around the ends of the buckets and forms a cover therefor.

2. An elastic fluid. turbine comprisin a plurality of buckets and a support thcfegor, In combination with a metal ribbon that is wound in layers around the ends of the buckets and forms a cover therefor, and means for securing the layers to the buckets.

3. An elastic fluid turbine comprisin a plurality of buckets and a support there or, in combination with a cover for the free ends of the buckets which is wound around the bucket ends in layers one on top of the other, and individual means for securing the cover in place at a plurality of oints.

4. An elastic fluid tur ine comprisin plurality of buckets and a su port there o made of thin flexible and perforated material which is wound around the bucket ends, one turn on top of the other with the'perforafor which pass through said perforations.

5. An elastic fluid turbine comprisin a plurality of buckets and a support there f or, in combination with a cover for the bucket ends made of thin metallic ribbon wound around the bucket ends one turn on top of and resting on the other, the said ribbon gral with the buckets which perforations, and are riveted over attheir ends to secure the cover in lace.

6. Anelastic fluid turbine comprising a plurality of buckets and a support therefor, in combination with a cover forming a wall of the bucket spaces made of a long, thin ribbon and wound a number of times around the ends of the buckets, and means located at each bucket for attaching the turns.

7. An elastic fluid turbine 'coinprisi a plurality of buckets and a support there or, 111 combination with a cover orming as wall of the bucket spaces which is made of a' thin,

to form successive layers, the sides of said ribbon being curved to compensate for the inclination of the bucket ends.

8. An elastic fluid turbine comprising a plurality of buckets and a support there r, 1n combination with a cover orming a wall of the bucket spaces which is made up of a thin metallic ribbon wound around the bucket ends to form la ers, and a meansto secure the outer end of the ribbon. and preing di placed by centrifugal.

vent it from I force.

in combination with a cover or the buckets tions registering, and securing means, there being perforated, and tenons formed inte-,'

pass through the metal ribbon wound around the bucket ends 9. An elastic fluid turbine comprisin a In witness whereof, I have hereunto set my pluralitg of buckets t1mind a support tlflere or, hand this 26th day of March, 1907. i

m com inntion wi a covering or the bucket ends that also forms a wall of the ALEXANDER M 5 bucket spaces, the said cove being wound Witnesses:

more than once around the hue ets and their JOHN A. MCMANUS, J r.,

- support. 7 Pmmr F. HARRINGTON. 

